Move the actual writing to a free function

Author: tiif

src/shims/unix/fd.rs

@@ -583,7 +583,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 fd.pread(communicate, &mut bytes, offset, this)
             }
         };
-        let res = write_byte_helper(buf, bytes, result, this)?;
+        let res = read_byte_helper(buf, bytes, result, this)?;
         this.write_scalar(res, dest)?;
         Ok(())
     }
@@ -617,27 +617,12 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             this.write_scalar(Scalar::from_target_isize(res, this), dest)?;
             return Ok(());
         };
-
-        let result = match offset {
-            None => fd.write(&fd, communicate, &bytes, this),
-            Some(offset) => {
-                let Ok(offset) = u64::try_from(offset) else {
-                    let einval = this.eval_libc("EINVAL");
-                    this.set_last_error(einval)?;
-                    this.write_scalar(Scalar::from_target_isize(-1, this), dest)?;
-                    return Ok(());
-                };
-                fd.pwrite(communicate, &bytes, offset, this)
-            }
-        };
-
-        let result = result?.map(|c| i64::try_from(c).unwrap());
-        let res = this.try_unwrap_io_result(result)?;
-        this.write_scalar(Scalar::from_target_isize(res, this), dest)?;
+        let res = write_byte_helper(offset, fd, bytes, communicate, this)?;
+        this.write_scalar(res, dest)?;
         Ok(())
     }
 }
-fn write_byte_helper<'tcx>(
+fn read_byte_helper<'tcx>(
     buf: Pointer,
     bytes: Vec<u8>,
     result: InterpResult<'tcx, io::Result<usize>>,
@@ -665,3 +650,26 @@ fn write_byte_helper<'tcx>(
         }
     }
 }
+
+fn write_byte_helper<'tcx>(
+    offset: Option<i128>,
+    fd: FileDescriptionRef,
+    bytes: Vec<u8>,
+    communicate: bool,
+    ecx: &mut MiriInterpCx<'tcx>,
+) -> InterpResult<'tcx, Scalar> {
+    let result = match offset {
+        None => fd.write(&fd, communicate, &bytes, ecx),
+        Some(offset) => {
+            let Ok(offset) = u64::try_from(offset) else {
+                let einval = ecx.eval_libc("EINVAL");
+                ecx.set_last_error(einval)?;
+                return Ok(Scalar::from_target_isize(-1, ecx));
+            };
+            fd.pwrite(communicate, &bytes, offset, ecx)
+        }
+    };
+    let result = result?.map(|c| i64::try_from(c).unwrap());
+    let res = ecx.try_unwrap_io_result(result)?;
+    Ok(Scalar::from_target_isize(res, ecx))
+}